Multiple point altimeter for use with toss bombing integrators



Nov. 3, 1959 J. RABINOW ET AL MULTIPLE POINT ALTIMETER FOR USE WITH TOSS BOMBING INTEGRATORS Filed Nov. 16,

. l l l l I INVENTORS RABINOW McLEAN aw/1L;

JACOB Q Q n 0 BY WILLIAM B.

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mm (W i 3 @w H w v of 102x052. E .w mobqmofiz 9 J ATTORNEY 2,911,573 Patented Nov. 3, 1959 fine MULTIPLE POINT AL'EEMETER FOR USE WITH TOSS BOMBING INTEGRATORS Jacob Rabinow, 'Eakoma Park, Md, and William B. McLean, Inyokern, Calif., assignors to the United States of America as represented by the Secretary of the Navy The present invention relates to altimeters and more particularly to a multiple point altimeterand an electrical circuit associated therewith cooperating to impart successive impulses at related altitudes to a toss bombing integrator for initiation and control thereof.

The present invention is intended to be employed primarily in conjunction with a toss bombing integrator for supplying the desired electrical impulses thereto necessary for the operation thereof. One common bombing tactic is for the attack plane to approach the target on' a level flight and then to maneuver into a downward glide or dive bombing course, the plane being directed for collision with the target, moving or stationary, until the attacking plane is Within the desired range of the target. Whereupon, the pilot maneuvers so as to pull out of his downward glide or dive and into an upward course. During this latter maneuver, the pull out operation, the bomb is released. This bombing tactic is commonly called toss bombing. One problem in such a bombing tactic resides in determining at what point of the pull out maneuver the bomb should be released to provide a hit on the target. Several reversing acceleration integrators have been designed for the purpose of automatically releasing the bomb at the proper point of the pull out maneuver for providing a hit on the target, and are herein referred to as toss bombing integrators.

One example of such a toss bombing integrator is fully described in the application for Letters Patent of Jacob Rabinow, for Reversing Acceleration Integrator, filed March 19, 1946, and having Serial No. 655,539, now Patent No. 2,496,310, and operates generally in the following manner: During the attack dive one impulse is fed into the integrator at one desired point, and a second impulse is fed thereto at a second point bearing a specific ratio of altitudes to the first point. The ratio of these two altitudes being known, assuming that the airplane continues its course at the same rate of acceleration, the integrator is so designed as to compute the time interval from the feeding of the first impulse thereto to collision with the target, and would operate to release the bomb at the moment of collision with the target if the airplane course were continued to collision. However, at a desired range from the target, after the second impulse, the pilot maneuvers the plane to pull out of the dive into an upswing, whichimparts a centrifugal force to the integrator mechanism so constructed as to yield thereto as a function thereof so as to speed up the bomb release timing mechanism, thereby releasing the bomb at the proper point during the pull out maneuver for a hit on the target. Thus, by feeding the two impulses into the integrator, the time for a predetermined fraction of the dive run to the target from the point of feeding the first impulse to the integrator is introduced therein, and the device being calibrated to the ratio of altitudes at which the two impulses are fed into it computes the total time from the first impulse until collision with the target. The pull out from the dive accelerates the timing mechanism through the centrifugal force imparted thereto, thereby accelerating the bomb release mechanism to provide for release of the bomb at, the proper time during the pull out maneuver so as to insure a hit on the target, all more fully described in the above-identified application.

The present invention is a control mechanism for such a toss bombing integrator as generally described above, in that it is designed to feed two impulses into the integrator at a predetermined ratio of altitudes, that is, according to the altitude ratio at which the integrator is designed to operate. Heretofore, the two signals necessary for the operation of the integrator have been controlled by means of two fixed points on a control altimeter, thereby restricting the bombing operation to a specific range of altitudes as determined by the two points chosen on the altimeter. The present invention is designed to overcome this limitation and provide for greater maneuverability of the attacking plane, and is so constructed as to afford the bombing plane substantially a complete freedom of altitude ranges in its attack run. This is essentially accomplished by using a plurality of contacts on the control altimeter, successive contacts corresponding to a constant ratio of altitudes, and by a suitable circuit connected to said contacts whereby any two successive contact points operate to give the desired signals to the integrator at the predetermined ratio of altitudes, thereby enabling the proper point for release of a bomb to be determined by the integrator over a large range of altitudes.

It is, therefore, one object of the present invention to provide an altitude responsive switch for use with a toss bombing release integrator.

Another object of the present invention is to provide an altitude responsive signalling device for use with a toss bombing release integrator for feeding signals thereto at a predetermined ratio of altitudes over a wide altitude range.

It is a further object of the present invention to pro vide a signalling device for toss bombing release integrators having a plurality of altitude related switch contacts for operating a signalling circuit over a desired range of altitudes, whereby any two successive switch contacts may be employed during a toss bombing attack run to supply the necessary signals to be fed to the integrator, thereby enabling the integrator to compute the proper point for release of the bomb during the toss bombing maneuver and affording to the attacking plane a large range of altitudes over which its bombing run may be made.

. Still another object of the present invention is to provide a signalling device for toss bombing release integrators which functions over a wide range of altitudes to impart the desired signals thereto in any desired portion of said altitude range.

' A still further object of the present invention is to provide an electronic signalling circuit for such a device which functions to produce said signals in any desired portion of said altitude range, and is so designed as to insure against accidental or undesired signals during the operation thereof.

Other objects and advantages of this invention will be apparent to those skilled in the art from a consideration of the following detailed description of the present invention, made in conjunction with the accompanying drawing which is a wiring diagram of' the present invention.

Referring to the drawing, numeral 10 denotes an altimeter of any desired type having a pointer 11, and a plurality of contact points 12 fixed to the altimeter dial 13. The contact points 12 are arranged on the dial along the are described by the pointer 11 so that contact may be made by the pointer successively with the various contact points. Pointer 11 is included in the electrical system by means of lead 14 electrically connected to the pointer shaft, while the various contact points 12 are electrically tied together by means of connecting lead 16 and are all included in the electrical circuit by means of lead. 15.

The electrical system of which the altimeter pointer and contact points on the altimeter dial form a part includes a grid-controlled arc tube 17, commonly called a thyratron tube and herein referred to by that term, acontrol or operating circuit therefor comprising a biasing voltage supply 18, a voltage divider 100, an operating voltage supply 19, two condensers 101 and 102, resistor elements 103, 105 and 106, and a master switch 20, and ,a relay circuit comprising three relays 33, 50 and 63.

voltage supply 18 through the voltage divider 100, and

,no current can flow between the cathode 22 and the anode 23 of tube 17. As the attack run is begun and the desired dive course has been attained by the plane, the pilot or bombardier closes the switch but, still assuming that pointer 11 is not in engagement, With 7 any when pointer 11 first engaged the contact point 12, but

of the contact points 12, the greater potential of the operating voltage supply 19 is still in an open circuit because thyratron tube 17 is non-conductive.

As the pointer 11 traverses the altimeter dial 13 during the airplanes decent in its diving fiight, it engages one of the contact points 12, thereby enabling the potential from the biasing supply 18 to be applied to the condenser 102 by means of leads 111, 107, and 14, thejpointer 11 and the particular contact point 12, and the leads 16 and 15, causing a surge of current to condenser102 thus lower ing the positive potential of the cathode-22, suificiently to make tube 17 conductive. After the thyratron' tube becomes conductive, the circuit of potential source19 is completed by means of leads 110 and 107, resistors 70, 71 and 105, tube 17, lead 34, contact 30, contact 32, lead .35, the coil of relay 33, and leads 36 and 66,.thereby.

raising the potential of the cathode 22 and condenser 102. This firing of tube 17 initiates the relay circuit, by means of the coil of relay 33, as discussed in detail herein below,and feeds a signal to the toss bombing integrator. Thyratron tube 17 is then quenched. As the diving maneuver of the plane is. continued, altimeter pointer 11 continues to traverse the dial 10 and breaks from the particular contact 12, thereby breaking the circuit to the the operating voltage 19 was in an open circuit because switch 20 was open. Now, with switch 20 closed, the tube 17 is non-conductive, for the initial surge of current has ceased. Therefore, the tube 17 remains inactive until the pointer engages the next oontact point, whereupon the first firing of tube 17 occurs. H

An additional feature of the thyr atron tube circuit resides in the fact that this circuit does not permit a second firing of the thyratron tube by an interruption of the circuit through a momentary break between the pointer 11 and a contact 12, as may be caused'by a faulty contact between said elements due to particles of dirt or the like on the contact or pointer. As described above,,when

switch 20 is closed and pointer 11 moves into engagement 7 with a contact point 12, a surge of current is caused to flowfrom the anode plate 23 to thecathode 22 of tube 17. A subsequent disengagement of pointer llfrom the particular contact 12 followed by reengagement of said pointer with another contact 12causes a second surge of current through said tube if switch 20 is held closed. Provision is made in the present circuit, therefore, to prevent an accidental second .firing of the tube as may be caused by a brief interruption of the contact between ,pointer'll and theparticular contact12 with which it is engaged after the first firing of the tube has been quenched by the relay circuit, as is fully described below. This is accomplished by means of the condenser 102 and the high resistance 103 shunted across it'.. This arrangement prevents a momentary break between the pointer 11 and, a contact point 12 from substantially affecting the voltage set-up of the circuit because of the large capacitance of condenser 102 and high resistance of element 103. When such a momentary break occurs, condenser 102 discharges relatively slowly through the resistor 103, thereby substantially maintaining the circuit in its status quo for the duration of such a momentary interruption. However, on interruption of the. pointer and contact engagement fora substantialperiod of time,

condenser 102. The switch 20 is maintained in closed' position, but since the pointer 11 is not inengagement with any contact point 12, condenser...102 discharges throu resistance 103,

As the plane continues to descend in 'its dive the pointer llengages the contact point lzz'nextlower with respect to altitude. With the switch 20 maintained in closed position and the condenser 102 having discharged through resistor 103 during the time interval between contacts, the thyratron tube 17 is again fired upon eng'agement of the pointer with said next'contact in accordance with the operation of this circuit as described above. Thus, at two successive altitudesan electrical impulse is fed into the relay circuit. i

Intthe event that at the time of initial closing of switch 20 pointer 11 is then in contact with one of the contactpoints 12, the thyratron tube 17 does not fire, because the condenser 102 has already been fully charged to the limit of the potentialsource 18, and the initial current resulting from this process of charging, which as described above functions to 'make the tube 17 conductiveQhas' ceased. The tube 17 was put into unbiased state by a surge of current from s'ource 18' to the condenser 102 such as is causedby the breaking of pointer 11 from one contact point 12 for a sufficient length of 'time as would be required'for it to engage the next contact point 12, the condenser 102 totally discharges, thereby setting up the circuit to enable the thyratron tubev 17 to produce its second conduction when pointer 11 engages said next contact point 12, in themanner described above.

Thus, by'closing switch 20 during the diving operation, it is apparent from the foregoing description of the operation of the'jthy'ratron tube 17 and its associated circuit that two surges ofa current are applied to the relay circuits at two'altitudes bearing a relation to each other in accordance with the position of contacts 12 on the dial 13, and as controlled by theengagement ofpointer 11 with said contact. points. 'The'first surge of current permitted by'the thy'ratrontube 17 paSSfis by means of leads 66 and. 3 6, through the coil of relay33, 'acrossjcoritacts 32 and 30, through tube 17, and through resistors 105,71 and 70 to the negative side ofthe battery. Excitation of relay 33 causes switch arm 40 tobreak-from'contact 42, its normally biased position, and to engage contact 43, and causes .switch ar'rni41 tofmo'ye from' its'normally biased position toengage'conta'ct v'44,thefor'jmer operating to feed a first impulse into' theintegratorby. anycanventional means. The engagement of switch arm 41 with contact 44 closesa circuit initiating ther'elay' 50 through leads 45, 52, .35," 36- and eojthereby'fcausing contact 30 r to break with contact 32,fits' normally biased position,

17. t This momentary break in thev relay circuit isequivalent to a momentary; opening of switch 20.;As1is app r nt 19m the foregoingdescrip 'on ,if while pointer11 is on a contact point 12 with switch 20 open, and switch 20 is then closed, no current will flow from the anode 23 to the cathode 22 of the thyratron tube 17, and the result is the same as if, while tube 17 is firing, switch 20 is momentarily opened, for this immediately puts voltage supply 19 in an open circuit by stopping the flow of current through tube 17. Thus, once quenched by this momentary break in the circuit, the thyratron tube cannot be again fired until pointer 11 has moved out of engagement with the particular contact point 12 and then subsequently engages a second of said contact points. Although the current flowing through control tube 17 and energizing relay 33 is quickly terminated by the action of relay 50 on switch arm 30, relay 33 is nevertheless maintained in energized state by means of switch arm 41 and contact 44 which enables current to flow to ground.

The energization of relay 50, by causing movement of switch arm 30 out of engagement with contact 32 and into engagement with contact 31, sets up the circuit for the second impulse to be imparted to the integrator through the switch arm 6t and its associated contacts 61 and 62 as controlled by the relay.63. As the bombing run is continued, switch 20 is' maintained in closed position, and as the altitude of the plane decreases altitude pointer 11 continues to traverse the altitude dial breaking with the particular contact 12 and eventually engaging the next lower contact with respect toaltitude. Engagement with the second contact 12 initiates a new surge of current through tube 17 in the same manner as was accomplished by the contact of the pointer with the first contact element, thereby energizing relay 63 through the circuit including lead 34, switchf arm 30, contact 31, lead 64, relay 63, and leads 65 and 66 back to the operating voltage supply 19. Energization of relay 63 causes switch arm 60 to break with contact 61, its normally biased position, and to engage contact 62, operating to impart the second signal impulse to the integrator by any conventional means.

It is therefore. apparent that the toss bombing attack may be carried out in any desired altitude range provided it is within the range of the contact points 12 on the altimeter dial 13. During the attack at any desired point in the dive bombing run the switch 2t} is closed. As the contact pointer 11 of the altimeter descends to indicate decreasing altitudes, it reaches one of the contacts 12, thereby initiating a surge of current through the control thyratron tube 17 which causes the switch arm 40 to break with contact 42 and engage contact 43 to impart a first impulse to the integrator. Also, switch arm 30 is brought out of contact with contact 32 and into engagement with contact 31 by means of relay 50, thereby quenching the thyratron tube and setting up the circuit to impart the second signal impulse to the integrator. As the bombing run is continued and the altitude of the plane continues to decrease, the pointer breaks With the first contact point 12 and engages the next lower contact point 12, with respect to altitude,'causing a second surge of current through control tube 17 to initiate relay 63 through switch arm 39, contact 33, and lead 64. Initiation of relay 63 causes switch arm 60 to break with contact 61 and to engage contact 62, thereby imparting a second impulse to the integrator. Thus, the bombing run may be begun at any desired altitude provided the dive run continues until the airplane is within the range of thecontact points 12 on the altimeter dial 13. While the desired dive run is made,closure of switch operates automatically to introduce into the integrator two electrical signals correlated with respect to each other, in a manner .described, hereinbelow, enabling the integrator to determine the proper point for releasing the bombs during the upswing maneuver from the dive in accordance with the trajectory of the bomb from the airplane to the target.

With each contact point l2 on the altimeter dial 13 located at interyals thereon representing five-sixths the,

altitude of thenext higher contact point, the integrator is designed so that upon being set in accordance with the time interval for the airplane to travel the first one-sixth of the distance to the target, it releases the bombs at the time the airplane would collide with the target if the airplane should continue on its dive course, it being apparent that five-sixths of the distance to target remains after the interval. The integrator operates on the assumptions, of course, that the airplane is directed on a collision course with the target during the aforementioned time interval, that the airplane remains on this course during the dive, and that the acceleration of the airplane while on this course is uniform. In accordance with a toss bombing attack, at some point during the attack, after said first one-sixth of the distance is traversed and the two impulses fed into the integrator, the airplane pulls out from the dive-into an upswing maneuver. The integrator is designed to respond to the upswing maneuver and in accordance with the centrifugal force created thereby to accelerate its timing mechanism in response to this force to release the bomb at the proper point in the latter upswing maneuver. In other Words, the integrator corelates the time interval between the two surges of current fed thereto during the dive maneuver with the centrifugal force of the upswing maneuver, as determined by the velocity of the airplane and the radius of the are described thereby, to release the bomb at the proper point on the upswing arc for a hit on the target.

Thetype of toss bombing integrators intended to be used in conjunction with the present invention are calibrated to a specific ratio of altitudes, that is, the ratio of the altitude of a particular contact to that of the. next lower contact. The present embodiment, as illustrated in the accompanying drawing, has its contact points 12 arranged in the altitude ratio of 6 to 5, that is, the indicated altitude for each contact point is six-fifths of the altitude for the contact point next lower on the altitude scale. Although illustrated as a 6 to 5 ratio in the embodiment herein described, this ratio is merely by way of example and not by way of limitation, for the present device may be employed with integrators calibrated to any desired ratio of altitudes, and the contact pointsflZ on the altimeter 10 may be correspondingly arranged to the desired ratio.

The specific description of the present invention herein contained is presented merely by way of example-and not by Way of limitation. Modifications of the present .device will be app'arentto those skilled in the art and are intended to be within the scope of thev invention as defined. by the appended claims.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon for therefor.

What is claimed is: I

I. In combination, an altimeter, a thyratron tube, a relay operative in response to conduction of said tube, and a plurality of contact points mounted on the altimeter dial, any two successive contact points representing the same predetermined fixed ratio of altitude, said contact points being positioned for engagementwith the altimeter pointer as said pointer traverses said dial in response to altitude, said contact points being electrically tied together, a source of potential sufficient to fire. said tube, coupling means seriallycoupling said source of potential through said points and the pointer to an element of said tube, said pointer and contact points forming amultiple contact switch, said relay operating in response to said tube to produce switching actions upon successive firings of said tube, any two successive switching actions thereby representing a fixed ratio of altitude.

2. In combination, a thyra-tron tube, a firing circuit therefor, relay means responsive to the firing of said tube, an altitude measuring device, a multiple contact switch controlled by said device included in said firing circuit, any two successive contact points of said multiple V V to altitude.

:7 contact switch spaced in the relation of a constant fixed 'ratio representing a. constant predetermined fixed ratio of altitudes, said contact points being electrically tied together, said'firing circuit allowing said tube to; fire upon closure of said multiple contact switch to any of its contacts by conveying a firing potential to said tube, said relay means operating in response to the firing of said tube to produce successive switching actions upon successive firings of said tube, switching actions thereby bearingra fixed relation to altitude in accordance with the ratio of said contact points thereto.

3. In combination, "a thyratron tube, a firing circuit therefor, a relay operated in series with said tube, and

an altitude responsive device, a multiple contact switch operated, in synchronism with said device and included insaid firing circuit, any two successive contact points of said multiple contact switch having the same fixed Cfl ratio of altitudes, said firing circuit firing said thyratron 4. In combination a thyratron tube, a firing circuit' therefor, an altitude responsive means, a multiple'contact switch included in said circuit for providing said tube with a firing potential, any two successive contact points of said multiple contact switch having the same fixed ratio of spacing to a third point thus representing the same fixed ratio of altitudes, said circuit firing said tube upon closure of saidmultiple contact switch to any of its contact points thereby producing a switching action, successive switching actions being thereby controlled 'by the switch and said switching actions bearing a fixed relation to altitude in accordance with the ratio of said contact points Incombination, an impulse controlling means, an operating circuit therefor; an altitude responsive device,

in said circuit having contact closures at a multiplicity of predetermined altitudes, any two successive contact points of said multiple'contact switch closing at a fixed constant ratio of altitudes, said'circuit operating said impulse controlling means upon closure of said multiple contact switch to any one of its contact points, successive operations of said impulse controlling means bearing a fixed relation to altitude in accordance with the ratio of said contact points to altitude.

6. In combination, a discharge tube, a firing circuit therefor, an altitude responsive means, a multiple contact switch operated by said means included in said circuit for changing the potential of an electrode of said tube, any two successive contact points of said multiple contact switch corresponding to a predetermined relation of altitudes, said circuit firing said tube upon olosure'of said multiple contact switch to any of its contact points thereby producing an impulse, successive impulses being thereby controlled by the switch and said impulses bearing a fixed relation to altitude; V

7. In combination, an electronic tube, a firing circuit therefor, and a pressure responsive multiple contact switch serially included in'saidcircuit to alter the potential on a control element of said tube, any two successive contact points of said multiple contact switch closing at the same predetermined fixed ratio of pressures, said circuit energizing said tube upon closure of any contact of said switch, and relay means successivelyresponsive to the energization of said tube in accordance with said ratio.

' a multiple contact switch operated by said device included plate circuit :operable upon the firing of said tube, a grid-cathode biasing circuit for normal biasing of said tube against plate conduction, an altitude measuring device, and a triggering circuit in electrical parallel relationship with said biasing circuit including a multiple contact switch driven in synchronism by said altitude measuring device, a capacitor in electrical series relationship with said switch, and a high resistance discharge shunt circuit across said capacitor, a second relay having a second operating coil and having second contacts for disconnecting said tube, said second operating coil being energized through said first contacts, whereby closure of said switch to any of its contacts enables a transient changeof said tubes grid-cathode bias by a momentary charging current flowthroughsaid capacitor lowering the relative potential of said tubes cathode '-'to enable initiation of tube plate conduction and hence energization of said operating winding, a subsequent firing of said tube after 'quenching being prevented, prior to reopening of said switch, discharging of said' capacitor, and reclosure of said switch, by the tubes normal grid-cathode bias. 9. An impulse generating circuit comprising a dischargetube, a plate circuittherefor, a relay having contacts and having an operating coil in the plate circuit energized upon the firing of said tube and'in turn quench-. ing said tube upon energization of the relay circuit by means of said contacts, a grid biasing circuit normally biasing said tube against plate conduction, a point of low potential, and 'a triggering circuit for said tube including a switch coupled to the point of low potential, a capacitor in electrical series relationship between said switch and the cathode of said tube, and a high resistance discharge shunt across said capacitor, wherein the closure of said switch momentarily lowers the potential of the cathode of said tube for firing said tube, said switch having a multiplicity of contacts successively spaced from one another by successively decreasing spacings, each such spacing being less than the one before by a constant predetermined fraction of the one before.

prising a thyratron tube, a discharge initiating circuit therefor, a first relay operative in series with the anodecathode circuit of said tube, an altitude measuring device, said discharge initiating circuit including a multiple contact switch responsive to said altitude measuring device having its contacts operable in a predetermined relation of altitudes, a cut-off biasing circuit coupled to the grid and cathode'of said thyratron, and wherein closures of said multiple contact switch to its ,various contacts partially shunt said cut-off biasing circuit to enable said tube to fire, a second relayv energized through contacts on said first relay, said second relay having contacts to disconnect said thyratron,'and a third relay set in elec trical series with said thyratron tube by second contacts on said second relay, whereby a second firing of said thyratron will energize said third relay. 1

11. A switching circuit comprising a thyratron tube; a discharge initiating circuit therefor, a relay having contacts and a coil connected in series with the anode-cathode circuit of saidthyratron tube, an altitude measuring de' vice,'said control circuit including a multiple contact switch responsive to said device wherein contacts of said switch are operated in relation to one another in a con stant fixed ratio of altitudes, each contact of said switch being connected to fire said thyratron tube and thereby energize said relay, a second relay having contacts anda coil operated through contacts on said first-mentioned relay, contacts on said second relay being-arranged to disconnect said thyratron tube, and a third relay set in 8. An impulse generating circuit comprising a thyratron tube, ,a plate circuit therefor, a first relay having a first operating winding and having first contacts in said serial relation with said thyratron tube by contacts on said second relay. 7

UNITED STATES PATENTS References Cited in the fileof this patent Re. 23,426

(Other references on following page) 10. For use in a toss-bombingsystem, a circuit com- Macgeorge Oct. 13, 1951 UNITED STATES PATENTS Swart Oct. 16,1934 Scheer Oct. 30, 1934 Anderson et a1. Feb. 4, 1936 Hertwig et a1 July 28, 1936 Koch Mar. 3, 1942 Burger et a1 Mar. 24, 1942 

